A strew slide of Pleurosigma strigosum and other diatoms from Havre (presumably Le Havre, Normandy, France). Marine species. Mounted in Hyrax and the mountant has yellowed. Prepared by JA Long. As well as the strew, I imaged one with the 40x Leitz Pl Apo 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 28 images stacked in Zerene (Pmax).
Pleurosigma strigosum W.Smith, 1852. Published in: Smith, W. (1852). Notes on the Diatomaceae with descriptions of British species included in the genus Pleurosigma. Annals and Magazine of Natural History, Series 2 9: 1-12, 2 pls. Page 7, Plate 1, Figure 6.